I don't think I have posted a fully coherent explanation of the Eco-floor idea elsewhere, so I thought I would add one here so people can get an at-a-glance view of it, and have the opportunity to contribute to its development - or come up with something even better.

There are several threads feeding this idea:

1. Mesh floors seem to suit only a limited climatic range - mostly mild and moist - and solid floors are problematic in other ways, including a build-up of moisture and rot.

2. Bees need total control - as far as that is possible - of their indoor environment to avoid extreme variations in outside temperature and humidity, which otherwise cause them a great deal of extra work.

3. Temp and humidity control is key to optimum maintenance of hive atmosphere, and therefore (I assume) to their ability to manage Varroa and other pests and diseases.

4. In nature, bees share their hollow trees with many other bugs and fungi, while conventional beekeepers do their best to keep such things out of their hives. It seems likely that there are unsuspected symbiotic relationships at play, which have unknown - but presumably beneficial - effects to bee colonies. One such is likely to be Stratiolelaps scimitus (see http://www.niagarabeeway.com/bio-control-for-varroa-mite.html).

From these threads, I developed the idea of a 'living floor', comprising habitat similar to that found in a hollow tree, which will accommodate bugs like Stratiolelaps, earwigs and woodlice - all commonly found in hives already - along with various fungi, bacteria and whatever else is happy to live there. Bees will be in direct contact with this habitat to the extent that they choose - given that they don't spend much time on the floor whatever it is made from.

The filling material should be capable of absorbing any excess moisture in the hive and act as a reservoir to help keep the atmosphere at their desired relative humidity.

I am all for reproducing as natural a habitat as possible for bees(am seasoning a large log I plan to hollow out and cut into 'boxes' this summer); however, and please correct me if I'm wrong, but if the bees are determined to remove the sawdust/vermiculite, does that not indicate they don't want it there? Yes, there are a number of critters that share hollow logs with bees in nature, and no doubt there are beneficial symbiotic benefits, but if a layer of mulch in the bottom of a colony was that beneficial, would not bees have evolved to leave it there?

The bees in question were in a hive some distance from here, which was being supervised by a beekeeper not particularly experienced with top bar hives. They had been transferred by chop & crop and were in too confined a space for a growing colony, so I assume they removed the floor material in an attempt to expand downwards, as they could not do so sideways.

I think it is true that bees don't care for loose, lightweight material in their hives and will remove it, which suggests that something of the weight and consistency of wood chips is better than only sawdust or vermiculite. I have no real evidence to support this, but I think vermiculite may have a role to play in creating air spaces between the chips. This is the material that Stratiolelaps mites are supplied on by the breeders.

My feeling is that the bees don't like fresh sawn timber for some reason. I've seen this with swarms absconding from newly built hives. In a natural tree cavity, the debris in the bottom will be crumbled rotting wood, not fresh clean white wood shavings.
Certainly I have seen bees struggling with shavings 2-3 times their size and flying off with them for some considerable distance.... 40-50 feet.... before dropping them, so either I have stupid bees that make a lot of extra work for themselves or they don't want them anywhere near the hive. I've used these in top bar nucs/bait boxes.

I'm trying a mixture of dry grasses and leaves in my main TBH but it's a retrofit and I wasn't able to remove the mesh before I fitted it, so they don't have access to the floor medium which I regret but it was difficult making the trough a good fit with bees in situ. I like the idea of mature wood chips/bark. I have a bag of vermiculite but for some reason I'm not too keen to use it, perhaps because it's inert and I feel break down of the medium should be part of the process.

My current protocol is to leave fresh wood chips in a pile for a few weeks to 'mature' and absorb fungal spores. You can see the white mycorrhiza developing.

I don't have a fixed opinion about vermiculite - maybe it is unnecessary. The mites seem to like living on it and it seems to support moulds and possibly fungi, and I thought it might lighten the mix, but who knows!

We built our first top bar hives last spring with a mesh floor and I am very pleased that we changed over to the deep floor during the summer. We are not through our first winter yet but the bees appear very happy.

We have a garden shredder and I used the chippings from apple and hazel for our deep floor filling, mostly because that is what we had on hand at the time. Some plants are very heavily scented after going through the shredder (Magnolia, bay....) and while the scent may fade in time, the bees are so sensitive to smell that I think that whatever material is chosen should be of minimal scent. (Never any harm to state the obvious!) Also some plants have insecticidal qualities (like cedar) which could cause harm.

I left the chippings for a few weeks to dry out before putting them in the hive. They have remained dry on top and I don't know if they are damp underneath. The bees seem to keep the floor clean. I don't see dead bees or wax cappings strewn about. I have seen bees trying to remove small leaf particles. I wonder is it in their nature to move what they physically can move?

The first hive we (my husband ) built, he levelled off the bottom so it was flat for attaching the mesh. When he went to retrofit the deep floor it then had 90 degree angles and was 3 times the volume of the other hive which still had the angle from the hive body. So this is why I like pictures, I find it hard to describe this! I guess you could say, the flat bottomed hive has straight sides going down instead of continuing the angle of the hive and so has a larger volume.

I like the bigger volume but they both seem to work fine. As our site does receive some wind I am especially glad we switched to deep floor. With one colony I moved the bees 3 or 4 combs together at a time into a bait hive right in front of their entrance for a few days while we put on periscope entrances and the deep floor, Then another colony was transferred directly into the other end of the finished hive, again 3 or 4 combs at a time. (The hives are more than 4 and a half feet long as that was the length of timber we had). I am keen to intervene as little as possible and it seems like a big disruption. However I felt the bees settled very quickly and that it was for their long term good.

I saw your pictures, Kim - a lovely spot. Did we meet at Mike's place when I was over there in 2012?

The vertical-sided hive you describe is usually called the 'Tanzanian' pattern, while the sloped-sided version is the 'Kenyan'.

I prefer the Kenyan for a variety of reasons, but if the Tazanian works for you that's fine by me. You may be the only owner in the world of a Tanzanian with an Eco-floor, so I hope for more feedback in due course.

I think leaving the wood chips to 'mature' makes sense, both for reasons of absorbing spores and losing volatile oils that may be harmful. In addition, I'm hoping that the local Stratiolelaps population will also colonize it, which will save having to buy them in.

Yes, I did not explain myself well! Only the deep floor is Tanzanian box style. I only have Kenyan hives but the shape of the deep floor is affected by whether the bottom of the hive has been planed off. If I am able to capture this in pictures I will do so.

I like this idea. I think I'll put an eco floor on one of my Ware hives this year. Now they'll have wood shavings above and below. It sounds like I need to 'season' some of my sawdust. I usually get it from a sawmill so that it is still 'live' vs kiln dried. It should decay well and absorb moisture. Do you think I should mix in some of my compost (with or w/o bio-char) to speed up the 'aging' process?

In most parts of the US and I'd suspect CA as well, semi-rotted bark mulch is available at local gardening supply/landscaping outlets. This is the stuff I'll be loading into the base of an experimental "hive tower" currently in progress. The base consists of 4"X8"X16" masonry blocks bedded in gravel, supporting a 4"X4" post & beam stand and tightly enclosed by 1/4" fiber cement panels. Over-all dimensions to a bit less than 3' X 3' X 3'. The four-hive stack sitting on this stand will reach to another 7', (10' total height). The stand will hopefully protect against skunk, 'coon, 'possum and cold draft penetration into the open hive bottoms above, as well as providing a dandy spot for a mulch bed placed directly on the soil within. This undisturbed soil should allow enough upward capillarity to keep the mulch at a nice steady moisture level.
Stay tuned.
More design description near the end of the big condenser hive thread, started by Bernhardt in the Bee Health: pest ,diseases, etc. forum just above this one.
Charlie

Ages ago I posted photos in the photo section of our deep floor in a topbar hive. I have been meaning to update. The deep floor has sunk and the bees have built down just leaving a bee space above the sunken floor. The deep floor is also completely propolised! and I am therefore reluctant to bring the level up again by adding more material. It would give the bees loads more work to re-propolise and as for shortening combs? I guess if I very regularly checked and went through all the hives I would have been adding to the floor and avoiding this situation, perhaps.

There is a slight inconvenience of combs not being easily interchangeable (because they are slightly different lengths), However switching / moving combs is something I rarely do anyway. We (the bees and I) are happy (They're happy I'm happy!) with the deep floor. All our hives made it through the first winter and last winter I had losses but also strong survivors. None of our hives have been treated with anything. In one of the hives I didn't have enough topbars to cover the whole hive top so it was just the colonies topbars with follower boards either side within the hive, but the follower boards only go down to the deep floor and a mouse easily burrowed under the follower board. I simply overlooked that possibility!

I do wonder, with the floor propolised, if varroa can climb back onto the combs after they fall off the bees? A propolised deep floor may be defeating it's original purpose? My faith lies with the bees though. I should add that I am a beginner beekeeper and 2 winters is a mere drop in the ocean... but all the drops count.

http://www.biobees.com/forum/viewtopic.php?t=15985&highlight= This is the link to photos of our deep floor. I also posted photos of the deep floor the birds nest made in the bait hive, and after putting a nail across the entrance so birds couldn't do it again this year, the nail fell out and yes, another nest of chicks this year! and another ready made deep floor. I think the bees could remove most of the birds nesting material though.

Pleased to see here and elsewhere that people are experimenting with this idea. I think it applicable to any type of hive, including conventional frame hives, which could as easily be mounted on an 'eco-box' as on a normal floorboard.

I have never understood the logic of forcing bees to walk into a hive over a pile of debris and mites - at least the eco-floor will give earwigs and the like places to lurk so they can tidy up for the bees.

I have never understood the logic of forcing bees to walk into a hive over a pile of debris and mites - at least the eco-floor will give earwigs and the like places to lurk so they can tidy up for the bees.

So the funny thing is that one of the eco-floors warped a bit and there is a big enough crack that the bees use it like an entrance, meaning that they walk all thru the detris at the bottom of the hive anyway!

I would like to note that I started with a nuc last May and split 2x and all 3 made it thru the (mild this year) Vermont winter. Splitting really helps them get ahead of varroa.

All 3 hives had eco-floors. I can't say if it helped but it certainly didn't hurt!

The eco-floor was good protection against mice, extra good with no entrance at all. I put some comb in an empty Warre last year and this spring there was a huge mouse nest in it. I may try to populate the warre but it does need an eco floor or some way to winterize it to prevent mice from entering.

To be fair, the deep litter floor was originally proposed for a top bar hive, so there was no issue with comb being built below the "frames" as such.

I would advise against putting screed between the bees and the deep litter.

I retro fitted my first deep floor to a hive with a mesh floor and bees in residence, so the litter was below the bees. I was horrified a year later to find that the deep litter was a seething mass of wax moths and their larvae that were living off the wax debris that dropped through the mesh. The bees were unable to deal with this infestation of wax moth because they couldn't get to them but the wax moth could get through the mesh and try to colonise the comb, so the bees had a constant job of trying to prevent this. A weaker colony would not have been able to cope and even this strong colony will have had to devote significant bee power to this task instead of doing other more productive work. Surely if the frames need to be transferred to another hive the additional comb can just be removed.

You could just use it as an integrated pest management system because that comb will most likely be drone brood comb, so cutting it off when capped can help reduce varroa levels (I'm not condoning drone culling as such but just suggesting that on a small small scale like this where it is a problem, it is an option. The simplest thing to do would be just to top the deep litter up to the level you need, or you could place a piece (or pieces) of timber on top if the litter to take up the space and provide a "level" floor to the hive, so you have the best of both worlds. Insects may even prefer the environment below the timber to having it more open, as it should keep it more moist.

I've also been thinking of doing away with mesh on the bottom and using weed control fabric instead as this will allow some drainage and breathability but not as much as mesh, so should keep the atmosphere more moist, be a lot cheaper than mesh and easier to fit. I am proposing this for an horizontal top bar hive rather than anything else and obviously it would not give protection form mice or badgers etc. Suspended up off the ground as it is in an horizontal top bar hive, outside my back door with my cats patrolling, this shouldn't be an issue.

I am definitely keen on the eco-floor idea, though given caution by Barbara's mention of wax moth invasion! I wonder if there's a way to tackle this for the bees?
As to mice, if the hive has 'legs', doesn't that prevent the problem? They can't cope with an overhang, can they!? Or jump from the ground? Hmmmm .... Mighty Mouse!
We always have plenty of mulch from our extensive woodland garden, so it's going to be a fun time building the box.

David, the wax moth infestation was only a problem because there was mesh between the deep litter and the bee area above. The bees were not able to access the deep litter area to evict the wax moth, so they thrived down there. I haven't had a problem with the hive where the litter is open and accessible to the bees and only has mesh on the bottom of the litter trough.

Hi Barbara
That's a relief! I think if I go with the ecofloor and a periscope entrance, I'll be happy if the bees are!
Trawling through other threads, I note that you prefer entrance holes on the end(s). Given that we're in more or less the same neck o' the woods, I now wonder whether that would be worth a shot: it could prevent starving out, I guess. The great thing about TBHs is that you can drill holes any old where and try out different configurations (as long as you don't turn it into a sieve!) and plug spare holes with corks. (I just received a bag of 30 wine-bottle corks from eBay for £3.85.)
Now that I may have some spare National brood boxes, I'm toying with converting a couple into TBH nuc/bait hives: another project!

Conserving wild bees

Research suggests that bumble bee boxes have a very low success rate in actually attracting bees into them. We find that if you create an environment where first of all you can attract mice inside, such as a pile of stones, a drystone wall, paving slabs with intentionally made cavities underneath, this will increase the success rate.

Most bumble bee species need a dry space about the size a football, with a narrow entrance tunnel approximately 2cm in diameter and 20 cm long. Most species nest underground along the base of a linear feature such as a hedge or wall. Sites need to be sheltered and out of direct sunlight.